It is not a pretty end usually, unless you happen to know exactly what will help ease the pain and struggles that each patient/family member experiences. I just went through this with my Father - he died on Labor day. roughly 26 hours before he passed we were finally able to get the right dosage of his meds and get oxygen for him, which gave him a peaceful passing. 6 days prior to that he stopped eating and drinking.
Dad had severe sleep apnea and was non-compliant with CPAP, so his respiration even while awake was about 15 seconds of snoring and 45 seconds of not breathing for the previous 4-5 days. He would become alert while not breathing and the expression on his face was that of pure terror (he was suffocating). It was truly heartbreaking.
Condolences
Sad he’s gone, glad you were able to beat the medical professionals into giving him what he needed.